There are many types of calls that are being performed in various telecommunications networks. The public switched telephone network ("PSTN") handles voice calls between two voice terminals and has been adapted to handle data calls between two data terminals through use of modems and the like. Likewise, many data networks, such as the internet, handle data and voice calls between two terminals.
Wireless networks are also commonplace, and are typically connected to the PSTN through one or more mobile switches. Furthermore, the wireless networks can be connected to a data network through interface systems such as one using data interworking function technology. In this way, a mobile terminal operating in a wireless network can connect to a remote terminal through the wireless network and further through the PSTN or the data network.
For a user of a mobile terminal to initiate a data call, the mobile terminal must either use a modem for connecting through the PSTN or use an interface system for connecting through the data network. For example, a user of a laptop computer may wish to connect to a remote terminal. In the present example, the laptop is configured to use a code division multiple access ("CDMA") technique for communication in a wireless network. The laptop establishes a wireless connection to a base station controller ("BSC"), which is further connected to a mobile switching center ("MSC"), both of which are components of the wireless network. The MSC must then direct the call to an interface system such as an internet service provider or an interworking function system ("IWF").
The IWF provides two functions. First of all, it establishes control signal communications with the laptop using a predetermined protocol stack. The protocol stack is commonly used to support various communications in the wireless network. Secondly, the IWF supports a data connection to the remote data terminal. The data connection can either be through the PSTN or through a data network.
Once the call reaches the data network, the laptop queries a server by providing it with a name that identifies the remote data terminal. The server then performs a "look up" routine in a database and returns an address that identifies the physical location of the remote terminal.
A problem exists because the above-described description is only one-way. That is, there is no way for the remote terminal to contact the mobile terminal. This is because the mobile terminal does not have a physical location. In fact, the mobile terminal can be connected to one of many different MSCs in one of many different wireless networks. Therefore, there is no way to "look up" an address for the mobile terminal.
What is needed is a system and method for allowing a user to contact a mobile terminal in a wireless telecommunications network.